/* ============================================================
   MAX // FIELD GUIDE TO 3D PRINTING
   Technical-drawing / maker-bench theme — light, self-contained.
   No external fonts, no CDN. Monospace engineering vibe.
   ============================================================ */

:root {
  /* Paper & ink */
  --paper:      #f3efe6;   /* warm drafting paper */
  --paper-2:    #fbf9f4;   /* card / panel */
  --ink:        #181712;   /* charcoal ink */
  --ink-soft:   #6a6557;   /* faded pencil */
  --ink-faint:  #a8a294;

  /* Lines & grid */
  --line:       rgba(24, 23, 18, 0.14);
  --line-soft:  rgba(24, 23, 18, 0.07);
  --grid-major: rgba(24, 23, 18, 0.06);
  --grid-minor: rgba(24, 23, 18, 0.035);

  /* Accents */
  --filament:   #ff5a1f;   /* hot-end orange */
  --filament-d: #d83f0a;
  --teal:       #1f7a8c;   /* secondary / calibration */
  --acid:       #b6cf2a;   /* bed-leveling lime */

  /* Type */
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", "JetBrains Mono",
          Menlo, Consolas, "DejaVu Sans Mono", monospace;
  --sans: "Avenir Next", "Segoe UI", Roboto, system-ui, -apple-system, sans-serif;

  /* Metrics */
  --rule: 1.5px;
  --maxw: 1180px;
  --ease: cubic-bezier(.2, .7, .2, 1);
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--sans);
  color: var(--ink);
  background-color: var(--paper);
  /* engineering grid: fine minor lines + heavier major lines */
  background-image:
    linear-gradient(var(--grid-minor) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-minor) 1px, transparent 1px),
    linear-gradient(var(--grid-major) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-major) 1px, transparent 1px);
  background-size:
    24px 24px, 24px 24px,
    120px 120px, 120px 120px;
  line-height: 1.65;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; display: block; }
a { color: inherit; }

/* ---------- typographic system ---------- */
h1, h2, h3, h4 { font-family: var(--mono); font-weight: 600; line-height: 1.08; letter-spacing: -0.01em; }

.eyebrow {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--filament-d);
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
}
.eyebrow::before {
  content: "";
  width: 26px; height: var(--rule);
  background: var(--filament);
}

.lede { font-size: 1.18rem; color: var(--ink-soft); max-width: 60ch; }

/* monospace inline tag, e.g. PLA / 0.2mm */
.tag {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border: var(--rule) solid var(--ink);
  padding: 0.18em 0.55em;
  border-radius: 2px;
  white-space: nowrap;
}
.tag--accent { border-color: var(--filament); color: var(--filament-d); }
.tag--teal   { border-color: var(--teal);     color: var(--teal); }

/* ---------- layout shell ---------- */
.wrap { width: min(100% - 2.5rem, var(--maxw)); margin-inline: auto; }
.section { padding-block: clamp(3.5rem, 7vw, 6.5rem); }
.section--tight { padding-block: clamp(2.5rem, 5vw, 4rem); }

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 2rem;
  flex-wrap: wrap;
  border-bottom: var(--rule) solid var(--ink);
  padding-bottom: 1rem;
  margin-bottom: 2.5rem;
}
.section-head h2 { font-size: clamp(1.6rem, 3.5vw, 2.4rem); margin: 0.4rem 0 0; }
.section-head .idx {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--ink-faint);
  letter-spacing: 0.1em;
}

/* ============================================================
   HEADER / NAV
   ============================================================ */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: blur(6px);
  border-bottom: var(--rule) solid var(--ink);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand {
  font-family: var(--mono);
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  display: inline-flex; align-items: center; gap: 0.6rem;
  font-size: 0.98rem;
}
.brand .mark {
  width: 26px; height: 26px;
  border: var(--rule) solid var(--ink);
  position: relative;
  display: grid; place-items: center;
  background: var(--filament);
  color: var(--paper);
  flex: 0 0 auto;
  font-size: 0.8rem;
}
.brand .slash { color: var(--filament-d); }
.brand small { color: var(--ink-faint); font-weight: 500; letter-spacing: 0.18em; font-size: 0.6rem; text-transform: uppercase; }

.nav-links { display: flex; align-items: center; gap: 0.4rem; list-style: none; margin: 0; padding: 0; }
.nav-links a {
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  text-decoration: none;
  padding: 0.5rem 0.85rem;
  border: var(--rule) solid transparent;
  border-radius: 2px;
  transition: border-color .18s var(--ease), color .18s var(--ease);
  position: relative;
}
.nav-links a:hover { border-color: var(--line); }
.nav-links a[aria-current="page"] { border-color: var(--ink); }
.nav-links a[aria-current="page"]::after {
  content: ""; position: absolute; left: 0.85rem; right: 0.85rem; bottom: -1px; height: 2px;
  background: var(--filament);
}

.nav-toggle {
  display: none;
  font-family: var(--mono);
  background: var(--paper-2);
  border: var(--rule) solid var(--ink);
  border-radius: 2px;
  padding: 0.4rem 0.7rem;
  cursor: pointer;
  font-size: 0.8rem;
  letter-spacing: 0.1em;
}

/* ============================================================
   HERO
   ============================================================ */
.hero { position: relative; padding-block: clamp(3rem, 8vw, 7rem); overflow: hidden; }
.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}
.hero h1 {
  font-size: clamp(2.5rem, 7vw, 5rem);
  margin: 1.1rem 0 0;
  letter-spacing: -0.03em;
}
.hero h1 .hl { color: var(--filament-d); position: relative; white-space: nowrap; }
.hero .lede { margin-top: 1.4rem; }
.hero-cta { margin-top: 2.2rem; display: flex; gap: 0.9rem; flex-wrap: wrap; }

/* big technical illustration panel */
.hero-fig {
  position: relative;
  border: var(--rule) solid var(--ink);
  background: var(--paper-2);
  padding: 1.5rem;
  aspect-ratio: 4 / 4.4;
  display: grid; place-items: center;
}
.hero-fig::before, .hero-fig::after {
  content: ""; position: absolute; width: 14px; height: 14px;
  border: var(--rule) solid var(--filament);
}
.hero-fig::before { top: -7px; left: -7px; border-right: none; border-bottom: none; }
.hero-fig::after  { bottom: -7px; right: -7px; border-left: none; border-top: none; }
.hero-fig .figtag {
  position: absolute; bottom: 0.7rem; left: 0.9rem;
  font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--ink-faint);
}
.hero-fig svg { width: 86%; height: auto; }

/* corner registration marks on hero bg */
.regmark { position: absolute; width: 20px; height: 20px; pointer-events: none; opacity: 0.5; }
.regmark::before, .regmark::after { content: ""; position: absolute; background: var(--ink); }
.regmark::before { left: 9px; top: 0; width: var(--rule); height: 20px; }
.regmark::after  { top: 9px; left: 0; width: 20px; height: var(--rule); }
.regmark.tl { top: 14px; left: 14px; } .regmark.tr { top: 14px; right: 14px; }
.regmark.bl { bottom: 14px; left: 14px; } .regmark.br { bottom: 14px; right: 14px; }

/* ---------- buttons ---------- */
.btn {
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
  padding: 0.8rem 1.3rem;
  border: var(--rule) solid var(--ink);
  border-radius: 2px;
  background: var(--paper-2);
  display: inline-flex; align-items: center; gap: 0.6rem;
  cursor: pointer;
  transition: transform .15s var(--ease), box-shadow .15s var(--ease), background .15s;
  box-shadow: 3px 3px 0 var(--ink);
}
.btn:hover { transform: translate(-2px, -2px); box-shadow: 5px 5px 0 var(--ink); }
.btn:active { transform: translate(1px, 1px); box-shadow: 1px 1px 0 var(--ink); }
.btn--accent { background: var(--filament); color: var(--paper); border-color: var(--filament-d); box-shadow: 3px 3px 0 var(--filament-d); }
.btn--accent:hover { box-shadow: 5px 5px 0 var(--filament-d); }
.btn .arrow { transition: transform .15s var(--ease); }
.btn:hover .arrow { transform: translateX(3px); }

/* ============================================================
   STAT STRIP
   ============================================================ */
.stats {
  display: grid; grid-template-columns: repeat(4, 1fr);
  border: var(--rule) solid var(--ink);
  background: var(--paper-2);
}
.stat { padding: 1.4rem 1.5rem; border-right: var(--rule) solid var(--line); }
.stat:last-child { border-right: none; }
.stat .n { font-family: var(--mono); font-size: 1.9rem; font-weight: 700; line-height: 1; }
.stat .n .u { font-size: 0.9rem; color: var(--filament-d); }
.stat .l { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-soft); margin-top: 0.5rem; }

/* ============================================================
   CARD GRID (guides previews, feature cards)
   ============================================================ */
.card-grid { display: grid; gap: 1.25rem; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }

.card {
  position: relative;
  border: var(--rule) solid var(--ink);
  background: var(--paper-2);
  padding: 1.5rem;
  text-decoration: none;
  color: inherit;
  display: flex; flex-direction: column; gap: 0.75rem;
  transition: transform .18s var(--ease), box-shadow .18s var(--ease);
  overflow: hidden;
}
.card::after {
  content: attr(data-fig);
  position: absolute; top: 0.8rem; right: 1rem;
  font-family: var(--mono); font-size: 0.66rem; letter-spacing: 0.16em;
  color: var(--ink-faint);
}
a.card:hover { transform: translateY(-4px); box-shadow: 0 10px 0 -4px var(--filament), 0 14px 24px -16px var(--ink); }
.card h3 { font-size: 1.15rem; margin: 0; }
.card .num { font-family: var(--mono); color: var(--filament-d); font-size: 0.8rem; letter-spacing: 0.1em; }
.card p { margin: 0; color: var(--ink-soft); font-size: 0.95rem; }
.card .more { font-family: var(--mono); font-size: 0.76rem; letter-spacing: 0.08em; text-transform: uppercase; margin-top: auto; color: var(--filament-d); display: inline-flex; gap: 0.4rem; align-items: center; }
.card .icon { width: 44px; height: 44px; color: var(--ink); }

/* ============================================================
   GUIDE ARTICLE PAGES
   ============================================================ */
.doc { display: grid; grid-template-columns: 220px 1fr; gap: clamp(1.5rem, 4vw, 3.5rem); align-items: start; }
.toc {
  position: sticky; top: 88px;
  font-family: var(--mono); font-size: 0.82rem;
}
.toc h4 { font-size: 0.7rem; letter-spacing: 0.18em; text-transform: uppercase; color: var(--ink-faint); margin: 0 0 0.8rem; }
.toc ol { list-style: none; margin: 0; padding: 0; counter-reset: toc; }
.toc li { counter-increment: toc; margin-bottom: 0.1rem; }
.toc a {
  text-decoration: none; color: var(--ink-soft);
  display: block; padding: 0.35rem 0.5rem 0.35rem 0;
  border-left: 2px solid var(--line); padding-left: 0.7rem;
  transition: color .15s, border-color .15s;
}
.toc a::before { content: counter(toc, decimal-leading-zero) "  "; color: var(--ink-faint); }
.toc a:hover { color: var(--ink); border-color: var(--filament); }

.prose { max-width: 70ch; }
.prose h2 { font-size: 1.6rem; margin: 2.8rem 0 0.8rem; padding-top: 0.6rem; scroll-margin-top: 84px; }
.prose h2 .sec { color: var(--filament-d); font-size: 0.9rem; margin-right: 0.6rem; }
.prose h3 { font-size: 1.15rem; margin: 1.8rem 0 0.5rem; }
.prose p { margin: 0.6rem 0 1rem; }
.prose ul, .prose ol { padding-left: 1.3rem; }
.prose li { margin: 0.35rem 0; }
.prose a { color: var(--filament-d); text-underline-offset: 3px; }
.prose strong { font-weight: 700; }
.prose code {
  font-family: var(--mono); font-size: 0.88em;
  background: color-mix(in srgb, var(--filament) 12%, var(--paper-2));
  border: 1px solid var(--line); border-radius: 3px; padding: 0.1em 0.4em;
}

/* ---------- code block (Arduino sketch) ---------- */
.code-block { border: var(--rule) solid var(--ink); background: var(--paper-2); border-radius: 2px; margin: 1.6rem 0; overflow: hidden; }
.code-block .bar {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: 0.55rem 0.9rem; background: var(--ink); color: var(--paper);
}
.code-block .bar .fname { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.08em; }
.code-block .bar .dots { display: flex; gap: 0.4rem; }
.code-block .bar .dots i { width: 9px; height: 9px; border-radius: 50%; display: block; background: rgba(243,239,230,.3); }
.code-block .bar .dots i:first-child { background: var(--filament); }
.code-block pre { margin: 0; padding: 1.1rem 1.2rem; overflow-x: auto; }
.code-block pre code {
  font-family: var(--mono); font-size: 0.82rem; line-height: 1.65;
  color: var(--ink); background: none; border: none; padding: 0; white-space: pre;
}
.code-block .c { color: var(--ink-faint); font-style: italic; }   /* comment */
.code-block .k { color: var(--filament-d); }                       /* keyword  */
.code-block .s { color: var(--teal); }                             /* string   */

/* ---------- labelled diagram figure ---------- */
.diagram {
  border: var(--rule) solid var(--ink); background: var(--paper-2);
  padding: 1.5rem 1.5rem 1.1rem; margin: 1.6rem 0; position: relative;
}
.diagram::before, .diagram::after {
  content: ""; position: absolute; width: 12px; height: 12px; border: var(--rule) solid var(--filament);
}
.diagram::before { top: -6px; left: -6px; border-right: none; border-bottom: none; }
.diagram::after  { bottom: -6px; right: -6px; border-left: none; border-top: none; }
.diagram img { margin-inline: auto; width: min(440px, 100%); }
.diagram figcaption { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-faint); margin-top: 0.9rem; text-align: center; }

/* compact Morse reference grid */
.morse-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(86px, 1fr)); gap: 0; border: var(--rule) solid var(--ink); background: var(--paper-2); margin: 1.4rem 0; }
.morse-grid div { padding: 0.55rem 0.7rem; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); display: flex; align-items: baseline; gap: 0.5rem; }
.morse-grid b { font-family: var(--mono); font-size: 0.95rem; }
.morse-grid span { font-family: var(--mono); color: var(--filament-d); letter-spacing: 0.08em; font-size: 0.92rem; }

/* ---------- custom-character pixel map ---------- */
.bitmap { display: flex; gap: 1.6rem; align-items: flex-start; flex-wrap: wrap; margin: 1.4rem 0; padding: 1.3rem; border: var(--rule) solid var(--ink); background: var(--paper-2); }
.px-grid { display: grid; grid-template-columns: repeat(5, 22px); grid-auto-rows: 22px; gap: 4px; flex: 0 0 auto; }
.px-grid i { display: block; border-radius: 2px; background: color-mix(in srgb, var(--ink) 7%, var(--paper)); box-shadow: inset 0 0 0 1px var(--line-soft); }
.px-grid i.on { background: var(--filament); box-shadow: inset 0 0 0 1px var(--filament-d); }
.px-bits { font-family: var(--mono); font-size: 0.84rem; line-height: 26px; color: var(--ink-soft); margin: 0; }
.px-bits .b1 { color: var(--filament-d); font-weight: 700; }
.px-cap { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-faint); width: 100%; margin-top: 0.4rem; }

/* callout / note box */
.note {
  border: var(--rule) solid var(--ink);
  border-left: 6px solid var(--filament);
  background: var(--paper-2);
  padding: 1rem 1.2rem; margin: 1.5rem 0;
  border-radius: 2px;
}
.note .label { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.16em; text-transform: uppercase; color: var(--filament-d); }
.note.note--teal { border-left-color: var(--teal); }
.note.note--teal .label { color: var(--teal); }
.note p:last-child { margin-bottom: 0; }

/* spec / data tables */
.spec-table { width: 100%; border-collapse: collapse; font-size: 0.92rem; margin: 1.2rem 0; }
.spec-table th, .spec-table td { text-align: left; padding: 0.7rem 0.9rem; border: var(--rule) solid var(--line); vertical-align: top; }
.spec-table thead th { font-family: var(--mono); font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase; background: color-mix(in srgb, var(--ink) 4%, var(--paper-2)); border-bottom-color: var(--ink); }
.spec-table tbody tr:hover { background: color-mix(in srgb, var(--filament) 6%, transparent); }
.spec-table td:first-child { font-family: var(--mono); font-weight: 600; }

/* ============================================================
   GALLERY
   ============================================================ */
.filters { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-bottom: 2rem; }
.filter {
  font-family: var(--mono); font-size: 0.76rem; letter-spacing: 0.06em; text-transform: uppercase;
  border: var(--rule) solid var(--ink); background: var(--paper-2);
  padding: 0.45rem 0.85rem; border-radius: 2px; cursor: pointer;
  transition: background .15s, color .15s;
}
.filter[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.filter:hover { background: color-mix(in srgb, var(--filament) 14%, var(--paper-2)); }

.gallery { display: grid; gap: 1.25rem; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }
.print {
  border: var(--rule) solid var(--ink); background: var(--paper-2);
  display: flex; flex-direction: column;
  transition: transform .18s var(--ease), box-shadow .18s var(--ease), opacity .25s, filter .25s;
}
.print:hover { transform: translateY(-4px); box-shadow: 6px 6px 0 var(--ink); }
.print.is-hidden { display: none; }
.print-img {
  aspect-ratio: 4 / 3; position: relative; overflow: hidden;
  border-bottom: var(--rule) solid var(--ink);
  background:
    repeating-linear-gradient(45deg, var(--line-soft) 0 1px, transparent 1px 10px),
    var(--paper);
  display: grid; place-items: center;
}
.print-img svg { width: 72%; height: auto; transition: transform .4s var(--ease); }
.print:hover .print-img svg { transform: rotate(-3deg) scale(1.05); }
.print-img .cat {
  position: absolute; top: 0.6rem; left: 0.6rem;
  font-family: var(--mono); font-size: 0.62rem; letter-spacing: 0.12em; text-transform: uppercase;
  background: var(--ink); color: var(--paper); padding: 0.2em 0.5em; border-radius: 2px;
}
.print-body { padding: 1.1rem 1.2rem 1.3rem; display: flex; flex-direction: column; gap: 0.6rem; flex: 1; }
.print-body h3 { font-size: 1.1rem; margin: 0; }
.print-body p { margin: 0; font-size: 0.9rem; color: var(--ink-soft); }
.print-specs { display: flex; gap: 0.4rem; flex-wrap: wrap; margin-top: auto; padding-top: 0.4rem; }

/* ============================================================
   RESOURCES
   ============================================================ */
.res-grid { display: grid; gap: 1.25rem; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
.res-group { border: var(--rule) solid var(--ink); background: var(--paper-2); padding: 1.4rem 1.5rem; }
.res-group h3 { font-size: 1.05rem; margin: 0 0 0.4rem; display: flex; align-items: center; gap: 0.5rem; }
.res-group h3 .dot { width: 10px; height: 10px; background: var(--filament); display: inline-block; }
.res-group .sub { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-faint); margin: 0 0 1rem; }
.res-list { list-style: none; margin: 0; padding: 0; }
.res-list li { border-top: 1px solid var(--line); }
.res-list li:first-child { border-top: none; }
.res-list a { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; text-decoration: none; padding: 0.7rem 0; transition: padding .15s var(--ease); }
.res-list a:hover { padding-left: 0.5rem; }
.res-list a:hover .name { color: var(--filament-d); }
.res-list .name { font-weight: 600; }
.res-list .desc { font-size: 0.85rem; color: var(--ink-soft); display: block; font-weight: 400; }
.res-list .ext { font-family: var(--mono); font-size: 0.7rem; color: var(--ink-faint); white-space: nowrap; }

/* glossary */
.glossary { display: grid; gap: 0; border: var(--rule) solid var(--ink); background: var(--paper-2); }
.gloss-row { display: grid; grid-template-columns: 200px 1fr; gap: 1.5rem; padding: 1rem 1.4rem; border-top: 1px solid var(--line); }
.gloss-row:first-child { border-top: none; }
.gloss-row dt { font-family: var(--mono); font-weight: 700; color: var(--ink); }
.gloss-row dd { margin: 0; color: var(--ink-soft); font-size: 0.95rem; }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer { border-top: var(--rule) solid var(--ink); margin-top: 2rem; background: var(--paper-2); }
.footer-grid { display: flex; justify-content: space-between; align-items: center; gap: 1.5rem; flex-wrap: wrap; padding-block: 2rem; }
.footer-grid .meta { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.08em; color: var(--ink-soft); }
.footer-grid .meta b { color: var(--ink); }
.footer-dim { font-family: var(--mono); font-size: 0.68rem; color: var(--ink-faint); letter-spacing: 0.1em; }

/* ============================================================
   PAGE HEADER (interior pages)
   ============================================================ */
.page-head { padding-block: clamp(2.5rem, 6vw, 4.5rem) clamp(1.5rem, 3vw, 2.5rem); }
.page-head h1 { font-size: clamp(2rem, 6vw, 3.4rem); margin: 1rem 0 0; letter-spacing: -0.02em; }
.crumbs { font-family: var(--mono); font-size: 0.74rem; letter-spacing: 0.08em; color: var(--ink-faint); }
.crumbs a { text-decoration: none; color: var(--ink-soft); }
.crumbs a:hover { color: var(--filament-d); }

/* ============================================================
   MOTION — staggered load reveal
   ============================================================ */
@media (prefers-reduced-motion: no-preference) {
  .reveal { opacity: 0; transform: translateY(14px); animation: rise .7s var(--ease) forwards; }
  .reveal.d1 { animation-delay: .06s; }
  .reveal.d2 { animation-delay: .14s; }
  .reveal.d3 { animation-delay: .22s; }
  .reveal.d4 { animation-delay: .30s; }
  .reveal.d5 { animation-delay: .38s; }
  @keyframes rise { to { opacity: 1; transform: none; } }

  /* scroll-in for grid items handled via .in-view added by JS */
  .obs { opacity: 0; transform: translateY(18px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
  .obs.in-view { opacity: 1; transform: none; }
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-fig { width: min(380px, 100%); margin-inline: auto; order: -1; }
  .doc { grid-template-columns: 1fr; }
  .toc { position: static; border: var(--rule) solid var(--line); padding: 1rem 1.2rem; }
  .stats { grid-template-columns: 1fr 1fr; }
  .stat:nth-child(2) { border-right: none; }
  .stat:nth-child(1), .stat:nth-child(2) { border-bottom: var(--rule) solid var(--line); }
  .gloss-row { grid-template-columns: 1fr; gap: 0.3rem; }
}

/* nav collapses to a menu early — 7 links need the room */
@media (max-width: 900px) {
  .nav-links {
    position: absolute; top: 64px; left: 0; right: 0;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--paper-2); border-bottom: var(--rule) solid var(--ink);
    padding: 0.5rem; transform-origin: top; display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 0.85rem 1rem; border: none; border-bottom: 1px solid var(--line); }
  .nav-links a[aria-current="page"]::after { display: none; }
  .nav-links a[aria-current="page"] { color: var(--filament-d); }
  .nav-toggle { display: inline-block; }
}

@media (max-width: 680px) {
  body { font-size: 16px; }
  .stats { grid-template-columns: 1fr; }
  .stat { border-right: none; border-bottom: var(--rule) solid var(--line); }
  .stat:last-child { border-bottom: none; }
}